Incandescent lamp.



M. M. MERRITT. INGANDESGENT LAMP.

APPLIOATION FILED FEB. 24, 190B.

Patented Jan. 12, 1909.

INVENTDR;

Ti'Ys WITNESSES;

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HEW M-l MEBRITT; F- I E QN; mammal SS QNQB. Q' ELECTRIC LAMP COMPANY, OFCLEVELAND, OHIO, A CORPORATION OF mueoasia.

s ecification of L etterl Patent.

Eat-elated Jan. .1a,'1o.o'o.

np ilicafluafflled February 24, 1906: loam-No. 808,670.

To all/whom 'it may concern: I

Beit' known that I,

a citizen-f the- United States, residing at- Middleton, county of Essex;Eand-State of Massachusetts, have inventedan improve' mentin-Incandescent Lamps, of which the=- like letters; on the drawingsrepresenting like parts;

My invention relates to improvements in incandescent lamps and has forone object the provision-0i a lamp so constrnetedlas to prevent orgrender commercially impracticable its'renewal, or, in other words, the:substitutionor attempted substitution of a new filament ;fora;the oldone when the 'latteris burned out ortotherwise rendered uselessorinefiicien-t. I

It is-acommon practicete purchase at 31' relatively slight cost highgrade'lam'ps thus burned out, open the end or tip' of the lamp Thenew-filament having been" attached to the leading-in wires, the lam-pis'exhausted by the usual promss, the bulb sealed up, and the renewed orconverted lamp in condition "This renewing-process frequently conductedby irresponsible persons lacking the necessary skill and knowl-' ede inthe art and employing inferior materlals, so that fits product,- inanyevent' a'ninferior one isgvery often-a low grade-lam though havln 1every appearance of-a -hi g lr radeone y inventionaims to' correct t ispractice, preventing ossible injury-to the-reputation of the niakeno theorifiinal lamp a-nd d'ece' t ionpfthepnbl ic 'as we In the descr'i dembodiiment'ot my invertti'on 'thl's' is accomplished-' by 'erigaml l soco'nstruetm' the-lampasrender di or impossib e some one'or moreotthe'qis'ual stelps-l of theren'ewed rocess;

other object of my mventiong apart from and independent ofits utility'as a pre vention of the-renewal promise, is the-goonstruction of anincandescent lamp havingv an improved connection between the fil amentan the leading-in wires,

Myinvention will be best understood by reference to the followingdescription when taken in connectionwith the accompanyingillustration-of onespecifi'c embodinienttheflof; while itascopewill bemoreparficularly pointed' out'iin the'appended claims.

In 'the" drawings,Fi-%ure 1 shows a .laxnp einbod'ying one form 0' my Fi2 s'howsaon'an enlarged scale and ;-partia section" a detailshow'ingthe' filagentlattachment 'in' the lamp illustrated in Referringtothe drawings and .tothe ;em-"

bodiment of my invention which :I haivethere selected for illustration,there is shown a common .form of incandescent lamp proinvention, and.-

vided with theusual glass bulb a, cemented or otherwisesecured in theusual fashion to and 'within'th'e metal socket b and having the usualform of glass'stem a, through which pass the 'gleading-in wires 0!terminat ing in the sealed inplatlnum ends e; the lat.- ter connected"to the-filament 'f; 1

Inl theordinary lampjthe platinum ends. of-the leading-in wires haveeach a free or interior orti'on 'ro'ectin and replaoe-thezold filamentwith a'fresh'one. p p J beyond the stem,

which isordmariIy equa to or greater in lengthth'an the remainin'sealed-1n portion A nfthe-wire; When the "ament is'initially installed,the filament is placed with its ends' .m' the se ne fashion and by' thesamemo de .of attachment as'. originally.

In the described embodiment jot'my inventi'enIhaV e sl'ibstit'uted forthe bmder or paam memnie connection for the filament the leading-in wireand the filament end thereafter securedwithin' the same, preferably Ifirst attach onetoea'chend ofthe filament and secure them to theleading-in wire er'lds' when tha -filament is installed. The

and-platinum ends, the same herein comprising a'small sleeve '9,preferably of cop- I per ofother' suiitable material and of a sizeadapted approximately to fit over the plati- V nt1jm endofthe leading-inwire. While this sleeve; ifjdesired", could be first attached to sleevesbeing constructed of'suitable diame r' y may bemerely slippedioyerthe-fila mentends-and secured thereto wiaiany-suit:

I '40 platinum fifil'istitlltes one ofthe principal able tool whichactsto crinkle, crimpor otherwise compress or distort the sleeve. uponthe filament end. If it is desired to attach the sleeve to the filamentto secure good electrica c'ontact therewith, without mechanical.distortion, such result may readily be efi'ected by maintaining thesleeveand its loosely contained filament end in an atmosphere'of andcausing the latter'to penetrate and deposit upon the interstices betweenthe sleeve and the filament and secure the latterfirmly within thesleeve. This process may be carried on simply by passing an incandescingcurrent through, the filament and sleeve while they are sustained in anatmosphere of hydro-carbon gas. I Thefilament with its sleeve. attachedas described may be installed by inerely slipping the sleeve over theends of the leadingin wires and by aid of a suitable tool compressing orcrinkling the lower end of the sleeve, as indicated in Fig. 2.

It will be observed that the sleeve, however delicatelyit beconstructed, will have a uniting strength greatly in excess of theordinary graphite paste and that contact or union with the leading-inwires is required foria relatively short distance. Moreover, 80. thismode of attachment perniits the ends of the filament'and leading-inwires to lie'in abutment or opposition and does not require overlappingas does the pasted joint. The interiorly projecting or free portions ofthe platinum leading-in wire ends, therefore, may be, and preterably areof considerably less length than in the ordinary lamp and shorter thanthe sealed-in portions thereof. For example, it is feasible to reducethe free end to one-half or even oneuarter of its presentlength,'leaving a prolection of, say, one-sixteenth of an inch, or

. ess, instead of approximately one-quarter I of an inch as heretofore,thereby savin twenty-five per cent. or more on the mud amount ofplatinum required for the lead-- whlch, as is well-known,

in'g-in -wire ends, represents one of the most expensive-leatures of theincandescent lamp.

The absence of paste or otherporous matter in the joint is a markedadvanta e, for the absorption by the pasted'oint 0 moisture and gaseousmatter, whic must be excluded during the exhaustion rocess,conifiicultles in exhaustionw The 'pasteless joint, therefore,

rmits simplification and shortening of the eiihaustion process.

The illustrated form oi not on 1y '60 simpler and more 'eflic'ient thanthe aste, but permits .more rapid installation 0 the fila' ment andaffords a standard or certain mounting for the latter. -When the fila-*ment is asted tothe leading-in wires the 66" efieetivei'ength f thefilament is dependent decomposed hydro-carbon gas Fig. 2 I have shownthe free platinum end needed and useful strength for supporting lampneed in fact be applied to but one of -vantages usually accom thelatter.

in a measure upon theainount which its ends are caused to overlapthe'leading-in wires and this, particularly with negligent or care- Iless operators, varies through a considerable range. This obviouslycauses corresponding 70 variations in the; resistance, candle power,voltage,-and even the life of the filament. The use of the illustratedjoint gives c'ertainty as to the filament length and assurance that anynumber of filaments, when cut 7 5" to the prescribed length, will eachhave its intended efiec'tivej length when installed in its respectivelamp.

In the described embodiment of my invention the renewal of the lamp bysubstituting a fresh filament for the old one througlithe use of raphiteor other paste is practically impossi le, for the free ends 0f thefilament wires may be made so short as to render it- .impossible tounitc-a f esh filament thereto 86 by the pasting process. If desired,the lamp may be constructed so as to commercially prevent theinstallation of a fresh filament by any means whatsoever. For example,in

90 of the leading-in wire e materially weakened, as at h, which can bedone atthe time of the original lamp construction by an appropriatetool, so that while having all the filament, the stren t of theleading-in wire at e is less than t at of its attachment to the sleeve.Any attern t, therefore to withdraw or remove the seeve connection fromthe leading-inwire will result in breakmg oil the latter'close to thestem. t

will beevident that my invention as a means for preventing the renewalof the the two leading-1n wires. That is to say, it is effective forthis purpose if one leading in wire end only is shortened or weakenedas. described, or the sleeve connection employed atone joint only.

A sleeve, or other like connection, may, if desired, be employed inconnection with paste or other cementwithout the disadanying the use ofFor examp e, the sleeve alone may first be ap lied to the end of thelead- 1 ing-inwire' an clasped thereon. A small amount of aste havingbeen placed in the open end 0 thesle'eve, the filament end may be easilyand quickly inserted, the harden.-

' ing o fthe pas'tefirmly uniting the filament 2 to the sleeve. Theamount of pastereqnired is'so small, as to make a substantiallynonporous and pasteless 'oint, while the operation of iristallinggilament is easier than the usual process where an all pasted joint isemployed I v 7 While I have described and shown" one form of myinvention in detail for the sake of illustration. it is to be understoodthat the same is not limited to the details thereof 13c shown anddescribed, but that extensive modifications and departures may be madetherein without. deviatingfrom its spirit.

Claim-- l.' An incandescent lamp having a bulb, a stem, 2. filament, andleading-in wires, one of said leading-in wires being relatively weaknear the stem.

2. A non-renewable incandescent lamp having means forming a portion ofthe electric circuit of the lamp for injuring the lamp on the attemptedwithdrawal of the old filament.

3. A non-renewable incandescent lamp.

having means forming a portion of the electric circuit of the lamp forinjuring the lamp on the attempted substitution of a new filaing-in wire0 provided with-the weakened portion h, the filament fand sleeve g. 8.An incandescent lamp having a filament, a weakened leading-inwire, and ametallic sleeve connecting the ends of the filament and leading-in wire,said sleeve being compressed about one or both of the elements which itsurrounds.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

MATTHEW M. sMERRITT.

Witnesses:

NINA B. SHIRLEY, THOMAS B. BOOTH.

